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[IEEE 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Honolulu, HI, USA (2018.7.18-2018.7.21)] 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Near-Infrared Spectroscopy studies on TBI patients with Modified Multiscale Entropy analysis
摘要： Functional near-infrared spectroscopy (fNIRS) is an emerging non-invasive functional brain imaging technique, through detecting the changes of hemoglobin concentrations to investigate brain activities in various tasks. The aim of this study is to investigate the complexity of near-infrared spectroscopy signals during resting state and upper limb movements. Experimental study was designed by applying NIRS to collect the data especially for both healthy subjects and traumatic brain injury (TBI) patients. The modified multiscale entropy (MMSE) algorithm was employed to assess the complexity of fNIRS signals which may reflect the changes of brain activity when people underwent brain injury. The results that the mean MMSE of oxyhemoglobin values was lower in TBI patients compared to healthy subjects, indicated that MMSE was feasible to measure complexity of cerebral near-infrared spectroscopy signals in TBI patients, and that brain injury was associated with the decreased complexity of cerebrovascular reactivity. Moreover, measurement of complexity of brain signals has potential to provide significant guidance for rehabilitation.
关键词： cerebrovascular reactivity,modified multiscale entropy (MMSE),traumatic brain injury (TBI),brain activity,Functional near-infrared spectroscopy (fNIRS)
更新于2025-09-10 09:29:36
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Generation of sustained optimal entropy squeezing of a two-level atom via non-Hermitian operation
摘要： We investigate the entropy squeezing of a two-level atom in the Jaynes–Cummings model, and provide a scheme to generate the sustained optimal entropy squeezing of the atom via non-Hermitian operation. Our results show that the squeezing degree and the persistence time of entropy squeezing of atomic polarization components greatly depend on the non-Hermiticity intensity in non-Hermitian operation. Especially, under a proper choice of non-Hermiticity parameters, the sustained optimal entropy squeezing of the atom can be generated even though the atom is initially prepared in a no entropy squeezing state.
关键词： Jaynes–Cummings model,entropy squeezing,non-Hermitian dynamics,quantum optics
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE International Conference on Mechatronics and Automation (ICMA) - Changchun (2018.8.5-2018.8.8)] 2018 IEEE International Conference on Mechatronics and Automation (ICMA) - Full Quaternion based Color Image Fusion
摘要： In this paper, the local variance based full quaternions are used to describe image structure. The new structure is different from the real quaternion based method. Image fusion is performed by quaternion transform. The classical framework is applied to fusion images. The color wavelet information is expressed by quaternion wavelet. In order to measure the performance of several wavelet-based image fusion methods, an image fusion assessment method is used in this paper. Two types of source image are used to perform the experiments, four-level wavelet decomposition based assessment method is used to assess the images. Low frequency coefficient of wavelet decomposition matrix is used to fuse images by pixel average value method. Then the performance the methods are evaluated by some experiments. The results show that the information entropy of maximum pixel value and average grads is the greatest. The proposed method gives the best performance in the experiments.
关键词： Image fusion,Information Entropy,Full quaternion,Wavelet transform
更新于2025-09-09 09:28:46
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Study of memory deficit in Alzheimer’s disease by means of complexity analysis of fNIRS signal
摘要： Working memory deficit is a signature of Alzheimer’s disease (AD). The free and cued selective reminding test (FCSRT) is a clinical test that quantifies memory deficit for AD diagnosis. However, the diagnostic accuracy of FCSRT may be increased by accompanying it with neuroimaging. Since the test requires doctor–patient interaction, brain monitoring is challenging. Functional near-infrared spectroscopy (fNIRS) could be suited for such a purpose because of the fNIRS flexibility. We investigated whether the complexity, based on sample entropy and multiscale entropy metrics, of the fNIRS signal during FCSRT was correlated with memory deficit in early AD. fNIRS signals were recorded over the prefrontal cortex of healthy and early AD participants. Group differences were tested through Wilcoxon–Mann–Whitney test (p < 0.05). At group level, we found significant differences for Brodmann areas 9 and 46. The results, although preliminary, demonstrate the feasibility of performing ecological studies on early AD with fNIRS. This approach may provide a potential neuroimaging-based method for diagnosis of early AD, viable at the doctor’s office level, improving test-based diagnosis. The increased entropy of the fNIRS signal in early AD suggests the opportunity for further research on the neurophysiological status in AD and its relevance for clinical symptoms.
关键词： entropy,functional near-infrared spectroscopy,Alzheimer’s disease,free and cued selective reminding test
更新于2025-09-09 09:28:46
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Low-temperature synthesis of hydride semiconductor YH3?δ using Pt capped Y films and its chemical thermodynamics analysis
摘要： To decrease the temperature at which metallic yttrium (Y) reacts with H2 to form the semiconductor trihydride phase, we employed Pt capping layers as catalysts, and compared the result with those obtained when employing Pd, Ni, or their co-capping layers. It was found that Pt capping with 5 nm thickness makes trihydride phase majority when hydrogenated at 27°C, and allows us to obtain the trihydride phase with approximately 100% molar concentration when hydrogenated at 150 – 200°C. Chemical thermodynamics analysis of the experimental results reveals that both the enthalpy and entropy differences between pure states of trihydride phase and dyhydride phase with hydrogen vapor show monotonic hydrogenation temperature dependencies with their sign inversions at approximately the same temperature around 150°C, suggesting a particular thermodynamic mechanism specific to the hydrogen – yttrium system.
关键词： Platinum,Electron beam evaporation,Yttrium dihydride,Enthalpy,Yttrium trihydride,Yttrium,Entropy,Gibbs free energy
更新于2025-09-09 09:28:46
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Preparation of Amorphous Coatings of AlFeCoNiCuZrV Alloy by Direct Current Magnetron Sputtering Method
摘要： The amorphous coatings of AlFeCoNiCuZrV high entropy alloy were deposited by direct current magnetron sputtering (DCMS) in the mixed atmosphere of Ar and O2. A smooth amorphous coating was obtained. The microstructure and properties of the coatings were investigated. The results showed that the chemical composition, microstructure and mechanical properties of the amorphous coatings intimately relied on the concentration of O2 in the mixture atmosphere. When O2 flow ratio increased, the thickness and roughness of the coatings decreased. The maximum values of the hardness and the elastic modulus of the coating are 12 and 168 Gpa, respectively.
关键词： Properties,Amorphous coating,Magnetron sputtering,High entropy alloy
更新于2025-09-09 09:28:46
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Temperature and frequency effect on the electrical properties of bulk nickel phthalocyanine octacarboxylic acid (Ni-Pc(COOH)8)
摘要： The AC conductivity of nickel phthalocyanine octacarboxylic acid was investigated from 100 Hz to 1 MHz and temperature from 290 to 423 K. The AC conductivity was found to vary with frequency (σ(f)) and form two dispersion regions; the associated exponent factor “s” values were found to vary from 1.17 to 1.34 and from 0.42 to 0.67 (< 1). The value and temperature dependent of s are found in agreement with conduction mechanism models of large-polaron tunneling and the correlated barrier hopping, at the first and the second regions, respectively. The real and the imaginary parts of the dielectric constant were observed to decrease as the frequency increases indicating the pronounce contribution of low-frequency polarization mechanisms. Furthermore, the activation free energy ?F, enthalpy ?H, and entropy ?S of the sample were calculated as well.
关键词： enthalpy,polarization mechanisms,AC conductivity,activation free energy,dielectric constant,nickel phthalocyanine octacarboxylic acid,entropy
更新于2025-09-09 09:28:46
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A New Azimuth Ambiguity Suppression Algorithm for Surface Current Measurement in Coastal Waters and Rivers With Along-track InSAR
摘要： We present a new algorithm for suppressing azimuth ambiguities when measuring surface currents with an along-track interferometric (ATI) synthetic aperture radar in heterogeneous scenes, such as coastal waters or rivers. The key of the proposed algorithm involves a careful analysis of a parameter called the eigenvalue spectrum entropy (EVSE), which is defined as the entropy of the eigenvalue spectrum of the ATI covariance matrix computed in the Doppler domain. The physical meaning of EVSE is that it serves as a descriptor for the degree to which an unambiguous signal component and an ambiguous one are mixed. With the help of EVSE, azimuth ambiguities can be suppressed. Simulation results demonstrate that as compared with the conventional ATI method without azimuth ambiguity suppression, the proposed algorithm allows for a pronounced improvement in the current measuring accuracy. Other advantages of the proposed algorithm lie in the fact that it is not only adaptive, due to its ability to automatically capture the useful Doppler band whose width and position may both vary for different radar and scene parameters, but it also needs a minimal number of user inputs, making it a quite attractive algorithm for routine implementation.
关键词： eigenvalue spectrum entropy (EVSE),current retrieval,surface currents in rivers,ocean surface currents,azimuth ambiguities,Along-track interferometric (ATI) synthetic aperture radar (SAR)
更新于2025-09-09 09:28:46
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Medium range order and configurational entropy of vitreous silica
摘要： Two potential sets and three thermodynamic regimes were utilized in molecular dynamics simulations in the preparation of the corresponding structures of vitreous silica. Medium range order characterized by means of basic ring distributions is robust to both thermodynamic conditions and/or potentials sets. A strong correlation between topology and geometry is demonstrated; the correlation is much stronger for simple clusters/small rings. Configurational entropy was evaluated by the ideal mixing of the structural units of the decomposed silica network. Entropy responds to alterations in the heating/cooling rates and its behaviour yields an excellent agreement with the experimental specific heat capacity drops observed at the glass transition. It is suggested the glass transition of the simulated glass should be identified with the change of entropy and not with a change of enthalpy as is conventionally done.
关键词： medium range order,configurational entropy,vitreous silica,glass transition,molecular dynamics simulations
更新于2025-09-04 15:30:14
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Diversifying Deep Multiple Choices for Remote Sensing Scene Classification
摘要： Recently, deep models have shown powerful ability for remote sensing scene representation. However, the training process of these deep methods requires large amount of labelled samples while usual remote sensing image datasets cannot provide enough training samples. Therefore, the learned model is usually suboptimal. To solve the problem, this work focuses on obtaining multiple choices by training multiple models simultaneously, and then the human oracle can choose a proper one from these choices. However, training several models separately usually makes the obtained results similar. This paper tries to diversify the obtained choices by encouraging the obtained choices to repulse from each other. Experiments are conducted on Ucmerced Land Use dataset to validate the effectiveness of the proposed method to provide multiple diversified choices.
关键词： Remote Sensing Image,Cross Entropy,Diversity,Convolutional Neural Network,Classification
更新于2025-09-04 15:30:14